1. Field
The following description relates to a camera module and an electronic device that use a lens-customized point spread function (PSF) pre-estimated to correct blur characteristics caused by hardware defects such as distortions of lenses within the camera module, an assembly error of the lenses, or the like, and a method of operating the same.
2. Description of Related Art
Many electronic devices such as a smartphone are equipped with a camera module. Due to the recent trend for miniaturizing electronic devices, camera modules mounted in these electronic devices are often required to have a compact size and high performance.
Images obtained by such a camera module may be blurry due to several reasons. The blurriness of images reduces the image resolution.
The reasons for the blurriness observed in images may be attributed to hardware defects such as distortions of the lenses that occur during the manufacturing process of the lenses, an assembly error caused during the mounting of the lenses, or the like.
In an existing method of producing camera modules, in order to improve an average blur generated in each camera, the image correction to remove the blurring may be performed in a processor of an electronic device using a point spread function (PSF) estimated as a representative value with respect to all camera modules manufactured by the same production process to have the same specification.
In the existing image correction method as described above, because a PSF estimated as the representative value is used with respect to a plurality of camera modules manufactured to have the same specification by the same production process, the correction removes only the average blur. However, because each lens have different blur characteristics due to several causes and a camera module includes a unique set of these lens, the method may not provide appropriate correction of images for blur characteristics of lenses within individual camera modules.
In addition, during the process of manufacturing the camera modules, camera modules may be screened such that a camera module with lenses with blur characteristics below a predetermined reference levels may be determined to be defective. When the lens thicknesses are reduced in order to produce thinner camera modules to meet the specification requirements for miniaturized electronic devices, a greater amount of blurring is generated in comparison to a camera module that includes thicker lenses. Thus, a defect rate may be increased with the reduction of lens thickness, reducing a manufacturing yield. Therefore, a method for improving image resolution and increasing production yield is desirable.